检索结果-南通市图书馆

Possible early Neoproterozoic magmatism associated with slab window in the Pingshui segment of the Jiangshan-Shaoxing suture zone: Evidence from zircon LA-ICP-MS U-Pb geochronology and geochemistry

引用

Science China Earth Sciences 2009年第7期52卷 925-939页

作者： CHEN ZhiHong GUO KunYi DONG YongGuan CHEN Rong LI LongMing LIANG YiHong LI ChunHai YU XiMing ZHAO Ling XING GuangFu Nanjing Institute of Geology and Mineral Resources Nanjing 210016China Department of Earth Sciences The University of Hong KongHong KongChina College of Earth Sciences Jilin UniversityChangchun 130026China Zhejiang Pingtong Gorporation Shaoxing 310520China

We report here geochemical data, U-Pb zircon ages, and Hf isotopes for the high-Mg diorites (HMDs), Nb-enriched basaltic porphyrys (NEBPs) and plagiogranites (PLAGs) in the Pingshui segment of the Jiangshan-Shaoxing suture zone. The HMDs are characterized by high Mg# (>60), high Na and LREE contents, depletion of HREE and HFSE, and pronounced positive εNd(t) values of 7.0 to 7.7, similar to some adakitic high-Mg andesites. The NEBPs are relatively Na-rich (Na2O/K2O>6) and display high abundances of P2O5 (～1.00%), TiO2 (～3.08%) and HFSE (e.g., Nb=9.53–10.27 ppm). Their Nd isotopic compositions (εNd(t)=6.8–8.0) are comparable to those of the HMDs. The PLAGs are metaluminous (A/CNK=0.84–0.89) and sodic (Na2O/K2O>10). Their depletion in HFSE (e.g., Nb, Ta) is consistent with “SSZ-type” plagiogranite. Zircon LA-ICP-MS U-Pb dating yields an age of 932±7 Ma for the HMD, 916±6 Ma for the NEBP, and 902±5 Ma for the PLAG, respectively, indicating that they were products of early Neoproterozoic magmatism. The PLAGs exhibit relatively high zircon Hf isotopes and positive εHf(t) values of 11.0 to 16.2, consistent with their Nd isotopic data (εNd(t)=7.5–8.4). Such features are similar to those of oceanic plagiogranites in ophiolites and distinct from those of crust-derived granites. The PLAGs were most likely derived from partial melting of subducted oceanic crust in an active continental margin. Considering these results in the context of the regional geology, we suggest that a slab window in the subducting oceanic crust between the Yangtze Block and Cathaysia Block was possibly the principal cause for the unique arc magmatism in the area. The upwelling asthenosphere below the slab window may have provided significant thermodynamic conditions.

关键词： zircon LA-ICP-MS U-Pb dating geochemistry slab window early Neoproterozoic Pingshui of Shaoxing Jiangshan-Shanxing suture zone

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Distribution of TiN inclusions in Ti-stabilized ultra-pure ferrite stainless steel slab

引用

Journal of Iron and Steel Research International 2019年第9期26卷 962-972页

作者： Hao-jian Duan Ying Zhang Ying Ren Li-feng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

In order to clarify and control the silver defect on surface of cold-rolled sheet of the Ti-stabilized ultra-pure ferrite stainless steel, the distribution of TiN inclusions on the cross section of hot-rolled plate was studied using automated scanning electron microscopy/energy-dispersive X-ray spectroscopy inclusion analysis (ASPEX 1020 system). It was found that the number density decreases sharply from the surface to the center of the hot-rolled plate, whereas the average size increases. Then, the distribution of TiN inclusions on the cross section of continuously cast slab was investigated. Similarly, numerous small-sized TiN inclusions were generated at the subsurface of the slab. The average size rapidly increased and the number density dramatically decreased from the subsurface to 1/4 thickness, while from 1/4 thickness to 1/2 thickness, the increase in average size and the decrease in number density were slight. Thermodynamics results showed that TiN inclusion was formed below the liquidus temperature, which indicated that TiN inclusions could not be formed during secondary refining. Considering the microsegregation of solute elements and the equilibrium of TiN formation during solidification, TiN precipitated in the mushy zone when the solid fraction was close to 0.2. The growth of TiN was analyzed based on the diffusion-controlled growth model. With the increase in cooling rate, the time for TiN growth decreased and the size of TiN inclusions was diminished, which revealed the size distribution of TiN inclusions in the cast slab qualitatively.

关键词： TiN inclusion Ti-stabilized ultra-pure ferrite stainless steel Distribution in slab Thermodynamics Diffusion-controlled growth model

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Water modeling of mold powder entrapment in slab continuous casting mold

引用

Journal of University of Science and Technology Beijing 2007年第5期14卷 399-404页

作者： Qiaotong Lu Rongguang Yang Xinhua Wang Jiongming Zhang Wanjun Wang Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China

The optimal parameters were determined by the water modeling of slab casting. It was found that there are mainly three types of mold powder entrapment in slab continuous casting, i.e., the entrapment caused by the shearing flow near the narrow face of mold, the entrapment caused by vortexes around the submerged entry nozzle （SEN）, and the entrapment caused by the Ar bubbling. Both the velocity of the surface flow and the level fluctuation of the liquids are enlarged with increasing the casting speed, reducing the submersion depth of SEN, decreasing the downward angles of the nozzle outlets, and increasing the Ar flowrate, all of which increase the tendency of mold powder entrapment. Among the four above-mentioned factors, casting speed has the largest effect.

关键词： continuous casting slab mold mold powder water model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structural Optimization of Electromagnetic Swirling Flow in Nozzle of slab Continuous Casting

引用

Acta Metallurgica Sinica(English Letters) 2018年第12期31卷 1317-1326页

作者： Xiao-Wei Zhu De-Wei Li Chun-Lei Wu Katsukiyo Marukawa Qiang Wang Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern University School of Metallurgy Northeastern University School of Resources and Materials Northeastern University at Qinhuangdao

During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality ofthe slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in *** technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, therebycontrolling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle andpartly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structureand angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower thanthat without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at thetop surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial tothe growth of equiaxed crystal and decreased element segregation.

关键词： Continuous casting Submerged entry nozzle Electromagnetic swirling flow slab Numerical simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Material records for Mesozoic destruction of the North China Craton by subduction of the Paleo-Pacific slab

引用

Science China Earth Sciences 2020年第5期63卷 690-700页

作者： Yazhou FENG Jinhui YANG Jinfeng SUN Jiheng ZHANG State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China

It is well known that the destruction of the North China Carton(NCC)is closely related to subduction of the Paleo-Pacific slab,but materials recording such subduction has not been identified at the peak time of *** paper presents data of whole-rock major and trace elements and Sr-Nd-Hf isotopes and zircon U-Pb ages and Hf-O isotopes for Mesozoic volcanic rocks from the Liaodong-Jinan region in the northeastern NCC,in order to trace the subduction-related materials in their source and *** Mesozoic volcanic rocks in the Liaodong-Jinan region are mainly composed of two series of rocks,including alkaline basaltic trachyandesite,trachyandesite and trachyte,and subalkaline trachyandesite and *** U-Pb dating yields eruption ages of 129–124 Ma for these *** Early Cretaceous volcanic rocks are all enriched in LILEs(such as Rb,Sr,Ba and Th)and LREEs,depleted in HFSEs(such as Nb,Ta and Ti),indicating that they were originated from mantle sources that had been modified by subducted crustal ***,they have relatively heterogeneous and variable isotopic *** alkaline basaltic trachyandesite,trachyandesite and trachyte have enriched whole-rock Sr-Nd-Hf and zircon Hf isotopic compositions and mantle-likeδ18O values,suggesting that they were derived from low-degree partial melting of an isotopically enriched lithospheric mantle *** contrast,the subalkaline trachyandesite and andesite have relatively depleted isotopic compositions with zirconεHf(t)values up to+5.2 and heavy zircon O isotopic compositions with δ18O values of+8.1‰to+9.0‰,indicating that they were originated from a lithospheric mantle source that had been metasomatized by melts/fluids derived from the recycled low-T altered oceanic *** of these geochemical features suggest that the Early Cretaceous volcanic rocks in the Liaodong-Jinan region would result from mixing of mafic magmas with different *** magmas were originated from

关键词： North China Craton Early Cretaceous volcanic rocks Zircon Hf-O isotopes Subduction of the Paleo-Pacific slab

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Abnormal mold level fluctuation during slab casting of peritectic steels

引用

Journal of Iron and Steel Research International 2020年第2期27卷 160-168页

作者： Zhong-kuai Jiang Zhi-jian Su Cheng-qian Xu Jin Chen Ji-cheng He Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern UniversityShenyang 110004LiaoningChina Shanghai Meishan Iron and Steel Co. Ltd.Nanjing 210039JiangsuChina School of Metallurgy Northeastern UniversityShenyang 110004LiaoningChina

Abnormal mold level fluctuation is frequently observed in high-speed casting,especially for peritectic steels,which has been shown to severely deteriorate product *** an online electromagnetic sensor and an ibaAnalyzer are used to analyze the frequency and amplitude of massive mold level fluctuation data from the slab casting process of different steel grades using different casting speeds,slab widths and physical parameters of mold *** results show that in the slab continuous casting process of peritectic steels,the main frequency and equivalent amplitude of abnormal mold level fluctuations first increase and then decrease with increasing the carbon *** the production of various grades of steel,the main frequency of abnormal mold level fluctuation and the equivalent amplitude increase with increasing the casting speed,while the main frequency of abnormal mold level fluctuation changes little with increasing the casting *** main frequency of abnormal mold level fluctuation is positively related to the surface tension of the mold *** on these results,a new mechanism has been *** is shown that the abnormal mold level fluctuation is mainly induced by shell bulging while moving through the rollers,and resonance occurs when the frequency approaches the natural frequency of the molten steel in mold,which results in a large amplitude of the abnormal mold level *** on this mechanism,a new equation for the resonance frequency of molten steel is *** improved method based on this mechanism has proved to be effective in controlling abnormal mold fluctuations.

关键词： slab continuous casting Abnormal mold level fluctuation Resonance frequency Peritectic steel Surface tension

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Heat-transfer model on the improvement of continuous casting slab temperature

引用

Journal of University of Science and Technology Beijing 2004年第1期11卷 18-22页

作者： HongmingWang GuirongLi JunjieWang SchoolofMaterialsScienceandEngineering JiangsuUniversityZhenjiang212013China WuhanIron＆SteelCorpration Wuhan430081China

A heat transfer model on the solidification process has been established onthe basis of the technical conditions of the slab caster in No.3 steel works of Wuhan Iron & SteelCorporation, and the temperature field in the solidifying slab was calculated which was verified bythe measured slab surface temperature. The influences of the main operating factors includingcasting speed, spray cooling patterns, superheat of melt and slab size on the solidification processwere analyzed and the means of enhancing the slab temperature was brought forward. Raising thecasting speed to 1.3 m/min, controlling the flowrate of secondary cooling water and improving thecooling pattern at the lower segments of secondary cooling zone could improve the slab temperatureeffectively. And the increasing the superheat is adverse to the production of high temperature slab.

关键词： heat transfer continuous casting slab solidification mathematical model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical simulation of 3D electromagnetic–thermal phenomena in an induction heated slab

引用

Journal of Iron and Steel Research International 2020年第4期27卷 420-432页

作者： He-ping Liu Xian-hui Wang Liang-ying Si Jian Gong Central Iron and Steel Research Institute Beijing 100081China Shougang Zhixin Qian’an Electromagnetic Material Co. Ltd.Qian’an 064404HebeiChina

A mathematical model was developed to get an insight into 3D electromagnetic–thermal phenomena in an induction heated steel slab with a large width/thickness ratio by solving a fully coupled Maxwell equations and energy conservation *** spatial heat radiation between the slab surface and the refractory wall in an induction furnace was *** electromagnetic induction and temperature distribution features inside the slab with time evolution were *** effects of electromagnetic induction parameters,thermal conductivity of the material and process parameters on the induction heating process were theoretically *** results show that the spatial distribution of induction heat generation inside the slab is *** high work frequency and the low heat conductivity of slab increase the non-uniformity of slab induction heating *** radiative heat loss and heat transfer between the slab and the metal parts used for holding the slab have an important effect on the slab surface *** is necessary to separately control the current input in the multi-layer coil windings along the height direction of furnace and adopt the multi-step heating strategies with time evolution to improve the homogenization of the slab temperature.

关键词： slab Electromagnetic feld Induction heating Numerical simulation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

AN EXPERIMENTAL STUDY ON VERTICAL HYDRODYNAMIC FORCE ON A CIRCULAR slab NEAR FREE SURFACE BY WATER WAVES

引用

Journal of Hydrodynamics 2006年第2期18卷 184-191页

作者： LAN Ya-mei LIU Hua XUE Lei-ping CHEN Gang School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030China

An experimental study has been carried out to investigate the vertical force on a slab of sea-crossing bridge piers in the cases of different hydrodynamic conditions. The experimental study is divided into two parts in terms of regular waves and irregular waves. The hydrodynamic loads acting on the slab are measured by a six component balance and pressures on the bottom of the slab are measured by pressure transducers. It turns out that the vertical lbrce patterns can be considered as impact type and bouyant uplili type. For these two different patterns, time series of the vertical hydrodynamic forcc are measured and analyzed. The influences of wave height, wave period, clearance height of slab on the vertical force arc discussed in detail.

关键词： vertical impact forcc bouyant uplift force,waves slab

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Behavior of Transversal Crack on slab Corner During V-H Rolling Process

引用

Journal of Iron and Steel Research International 2006年第6期13卷 31-37页

作者： YU Hai-liang LIU Xiang-hua LI Chang-sheng Y. Kusaba State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China Sumitomo Metal Industries Ltd Fuso-cho 660 AMAGASAKI Japan

The behavior of transversal cracks on the surface of the slab corner during vertical and horizontal （V-H） rolling process with flat vertical roll and groove vertical roll was simulated by explicit dynamic finite element method. The closure and growth of crack and the contact pressure on surfaces of the crack in contacting zone between slab and roll during rolling process were analyzed. The results showed that during vertical rolling process, when the groove vertical roll is used, the maximum contact pressure on surfaces of the crack is 115 MPa, and the closure of crack is stable when the flat vertical roll is used, the maximum contact pressure on surfaces of the crack is 70 MPa, and it fluctuates greatly. During horizontal rolling process, when groove vertical roll is used, the contact pressure becomes zero which may accelerate the growth of crack when flat vertical roll is used, there is still contact pressure. The cal culated results are in good agreement with the results of test.

关键词： slab crack V-H rolling process FEM

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：